1. Field of the Invention
The present invention relates to a pull exerciser having at least one replaceable resilient cord.
2. Description of the Related Art
FIG. 1 of the drawings illustrates a conventional pull exerciser including two attachment members 20 each having a hole 201 , a resilient cord 1 having two ends respectively extending through the holes 201 of the attachment members 20 , with an end piece 11 being attached to each end of the resilient cord 1 , and two handles 2 respectively mounted to the attachment members 20. Each end piece 11 has a diameter greater than that of the hole 201 of the respective attachment member 20 to prevent the resilient cord 1 from disengaging from the respective attachment member 20 . A user may grasp the handles 2 and pull the resilient cord 1 with both hands to exercise muscles of the arms and the chest. A disadvantage of this conventional pull exerciser is that the resilient cord 1 could not be replaced with another resilient cord having a different elastic coefficient. Once the resilient cord 1 loses its resiliency, the whole pull exerciser has to be discarded. U.S. Pat. No. 6,676,576 discloses an adjustable pull exerciser including two attachment members, two handles respectively mounted on the attachment members, and at least one resilient cord attached between the attachment members. The resilient cord can be replaced with a new one when desired. Two positioning devices are respectively attached to the attachment members and each include a first positioning plate and a second positioning plate. Each of the first positioning plate and the second positioning plate includes at least one positioning hole in communication with outside via a reduced opening having a width smaller than a diameter of the positioning hole. The resilient cord is so sized to be extendible through the positioning holes of the first and second positioning plates. An end piece is fixed to each end of the resilient cord and has a diameter greater than that of the positioning holes of the first and second positioning plates. Each attachment member is adjustable in length to allow the associated first positioning plate and the associated second positioning plate to be spaced apart from each other for allowing removal/mounting of the resilient cord and to allow the associated first positioning plate to be in contact with the associated second positioning plate after removal/mounting of the resilient cord. However, when the resilient cord is subject to a relatively large force during use, the respective first positioning plates are liable to be spaced apart from or to turn relative to the respective second positioning plates, resulting in undesired disengagement of the resilient cord.